Small diameter/long reach spark plug with rimmed hemispherical sparking tip

1. A spark plug for a spark-ignited combustion event, said spark plug comprising:

a generally tubular ceramic insulator;

a conductive shell surrounding at least a portion of said ceramic insulator, said shell including at least one ground electrode;

a center electrode disposed in said ceramic insulator, said center electrode having a lower sparking end in opposing relation to said ground electrode with a spark gap defining the space there between;

said ground electrode extending from an anchored end adjacent said shell to a distal end adjacent said spark gap;

a metallic sparking tip attached to said distal end of said ground electrode, said sparking tip having a convex dome and a rim surrounding said dome, said rim disposed in surface-to-surface contact with said ground electrode, and

said convex dome and said rim have the same material content.

2. The spark plug of claim 1 further including a second metallic sparking tip attached to said lower sparking end of said center electrode.

3. The spark plug of claim 2 wherein said second metallic sparking tip has a convex dome and a rim surrounding said dome, said rim disposed in surface-to-surface contact with said center electrode.

4. The spark plug of claim 1 wherein said rim of said metallic sparking tip has a generally annular configuration.

5. The spark plug of claim 4 wherein said dome and said rim are generally aligned with one another along an imaginary central axis.